1. Field of the Invention
The present invention relates to a method for reinforcing the connection of a flat cable member and a method for manufacturing an image display unit using the flat cable member.
2. Description of the Related Art
Flat image forming apparatus constructed of an anode substrate (hereinafter, referred to as a face plate) including an anode electrode and a cathode substrate (hereinafter, referred to as a rear plate) including a cathode electrode are widely researched and developed in recent years. Examples of electron sources for use are those using field emission elements or surface-conductive electron emission elements. An example of the apparatus using the field emission elements is disclosed in U.S. Pat. No. 4,884,010. An example of the apparatus using the surface-conductive electron emission elements is disclosed in U.S. Pat. No. 5,066,883.
The display is not necessarily the aforesaid display using the field emission elements but various displays such as liquid-crystal displays, plasma displays, and EL displays are known.
The image forming apparatus include wires for display control such as wires for driving display elements. The connection between the wires and external circuits preferably use flat cable members (flat cables) in which multiple wires are bundled into flat shape with insulating substrates so as to insulate the wires from one another. For example, a flexible printed circuit board (FPC) extending to a driving circuit through an anisotropic conductive film (hereinafter, referred to as an ACF) or a tape carrier package (TCP) serving as a tape automated bonding (TAB) tape is connected to the wires.
The metal wires of the flat cable member are easily influenced by external forces or environment, whose migration resistance is decreased by application of voltage, thereby becoming incapable of maintaining the insulation between the adjacent wires.
Japanese Patent Laid-Open No. 06-314,866 discloses a method for forming a flexible printed-circuit board having a plurality of holes passing though in the direction of the thickness of a film protector on the periphery of a connecting conductor of a connection terminal connecting to a wiring pattern of the substrate of the display panel, the method comprising a soldering step of connecting the connecting conductor of the connection terminal of the flexible printed-circuit board with the wiring pattern of the substrate and a resin sealing step of filling up the connection terminal of the flexible printed-circuit board connected in the soldering step with insulative resin through the holes to form a resin sealed section so as to coat the soldered connection (refer to FIGS. 1A and 1B, 3A to 3C, and 4A to 4D).